Classifying apparatus



Dec. 26, 1933. HANS-JOACHIM JOHLIGE 1,941,147

CLASS IFYING APPARATUS Filed June 14, 1932 2 Sheets-Sheet 1 m v- TORHans-Joach/m lob/ige A TT ORNE Y 1933. HANS-JOACHIM JCQHLIGE 1,941,147

CLASSIFYIflG APPARATUS Filed June 14. 1932 2 Sheets-Sheet 2 Fig. 3 57HOG mvn l'foR Hans-Joachim Johlige Patented Dec. 26, 1933 UNITED STATESCLASSIFYIN G APPARATUS Hans-Joachim ,Johlige, Bohlen, near Leipzig,Germany, assignor to the firm Fried. Krupp GrusonwerkAktiengesellschaft,

Buckau, Germany Magdeburg- Application June 14, 1932, Serial No.617,121, and in Germany June 19, 1931 8 Claims. (Cl. 209-104) Myinvention relates to apparatus for classifying solid materials in bulkand more especially crude materials consisting of coarse pieces andlumps of indefinite shape and greatly varying size, such as or'es, coal,coke, lignite, stones, saline raw products, and like minerals, theobject being to segregate the material into classes or grades accordingto the size of the lumps,

The invention relates more particularly to mechanically operatedclassifying apparatus of the type comprising a plurality of spacedrotary shafts on each of which a great number of spaced disks is mountedwhich-taken as a wholeform a bed on which a layer of the material to beclassified is agitated and gradually advanced as the shafts rotate, sothat the smaller and medium sized lumps will drop through the said bedof disks, while the larger lumps are carried forward until they finallydrop from the extreme end of the apparatus.

In working with classifying apparatus of this type as widely used invarious industries, I have found that the results of their classifyingwork are often unsatisfactory for the reason that the gaps between thedisks of two adjacent shafts periodically vary in their effective width.In consequence thereof a considerable number of pieces of the materialwhich are oversize in respect to the specific size of the pieces of acertain 30 class will prematurely drop through the screen and will befound in a class containing relatively smaller lumps.

For instance pieces of the size of walnuts will be found in the classwhich should contain only pieces of the size of cherries; or lumps ofthe size of oranges will be found to have intruded into the class whichshould contain only lumps of the size of eggs.

Inversely in many cases it happens that a 40 noticeable number ofundersize pieces and even large proportions of pulverulent material arefound in classes of the material which should contain only larger lumps.My observations have shown that this latterdrawback generally arisesfrom specific working conditions inherent to classifying apparatus ofthe type concerned, which are unsatisfactory in two respects: Firstlybecause the layer of the material to be classified, on passing aheadover the bed of disks, is not sufliciently moved about, and raked upthroughout its whole depth from top to bottom so as to allow all thesmaller pieces to timely slide down from and between the larger piecesand to timely drop through the screen beginning at the early stages ofthe screening action-but are retained for excessive periods of time,viz, until they reach those sections of the screen provided for thelarger lumps; and secondly because the material in the course of thewhole classifying treatment is incidentally comminuted and is undulyreduced in size and value, with the result that small pieces are to befound in all classes of the classified material. For instance inclassifying soft, brittle and sticky material such as freshly minedbrown coal or lignite, dumped from the miners cars onto the classifying,screen, many small granules and even pulverulent material will be foundin classes which should contain only the largest lumps to be directlyburnt in furnaces, whereas the smaller grades of the fuel which are tobe briquetted contain many oversize lumps. The presence of smallgranules and of pulverulent material in the fuel of the larger gradeswhich are to be directly burnt is very objectionable because of thetendency of the smaller pieces and pulverulent material to choke the airgaps of the grate of the furnace and because of the heavy loss ofsubstance and weight occurring in the course of transportation from thescreening plant to the furnace.

I have also found that the output of screening plants of the typeconcerned is often considerably impaired through clogging of the screensespecially in cases when soft materials of a sticky nature such as browncoal or lignitewhich in their crude condition often contain over 50percent of waterare to be classified, the lumps of which tending tobecome pinched and retained between two adjacent disks of the screen.

According to my observations this drawback is due either to the entireabsence of appropriate members for stripping off the material pinchedbetween the disks, onto the fact that those stripping members have beenoccasionally overstrained and accidentally torn, broken or damagedotherwise.

My invention aims at providing an improved classifying apparatus of thetype and for the purpose set forth which is of relatively simple designand in which the above indicated drawbacks are eliminated.

One of the principal objects of the invention so to thus design theclassifying apparatus that its agitating, raking and screening actionupon the material is truly and fully efficient, so as to cause all thesmaller pieces to drop through the bed of disks already at the earlystages of the classifying work, and so as to obtain a larger output perhour when compared with apparatus I of the same size used heretofore.

In connection therewith the invention aims at providing an improvedclassifying apparatus by which a better classified material, viz, oftruly uniform sizes is obtained, of which the individual classes aresubstantially free from oversize and undersize pieces.

Another object of the invention is to efficiently yet relatively gentlyhandle the material-consistent with its physical properties, hardness,average size of the lumps, etc.during its passage over and through theclassifying apparatus, so that no noticeable comminution of the materialwill occur even with rather soft and fragile materials such as browncoal, lignite and the like.

Other object of the invention will become incidentally apparenthereinafter.

The nature and scope of the invention are briefly outlined in theappended claims and will be more fully understood from the followingspecification taken together with the accompanying drawings in whichFig. 1 is a fragmentary side elevation of the 1 feed end of aclassifying apparatus according to this invention diagrammatically shownby way of an example,

Fig. 2 is a plan,

Fig. 3 is another plan made in a reduced scale and showing the wholeclassifying apparatus,

having sections for small, medium, and large pieces,

Fig. 4 diagrammatically shows the arrangement of intermediary circulardisks concentrically arranged according to this invention between twoadjacent groups of disks,

Fig. 4a is only of explanatory nature, indicating by hatched lines thelarger two-cornered gaps which would temporarily exist between fouradjacent groups of disks, if there were no intermediary disks providedas in the case of Fig. 4.

Figs. 5 and 6 diagrammatically show structurally modified disks to beused in connection with classifying apparatus according to this in-.

vention.

As far as my research work has revealed amongst classifying apparatus ofthe type under consideration there are known two species-one in whichthe disks of two adjacent rotary shafts are arranged in staggeredposition to each other and are so shaped. that the disks of one shaftwill project into the spaces between the disks of the adjacentshafts-the object being to prevent clogging of the open spaces betweenadjacent disks-and another species in which the rotary shafts are spacedso wide apart from each other that the disks of two adjacent shaftscooperate only with their circumferential edges.

In my opinion the unsatisfactory working of classifying apparatus usedheretofore and referred to above is mainly due to the fact that thematerial under treatment during its agitation is simply pushed ahead bythe rotating disks in the general working direction i. e. along thelongitudinal axis of the apparatus, but is not effectively rolled aroundand trundled about in lateral direction across the bed of disks.

In contradistinction to known classifying apparatus the disks of whichare arranged in the manner indicated, I propose to structurallyaggregate into groups the disks, which are assembled on the rotaryshafts, and to angularly displace for cooperation said groups of disksrelatively to each other, so as to provide a number of steps over whichthe pieces of the material will roll aside and trundle about across thebed of disks; my experiments have shown that by appropriateto each otherthe screening effect of the apparatus is greatly enhanced: Alargeroutput per unit of time is obtained, and no undersize pieces willunduly remain on the bed of disks so as to intrude into classescontaining larger pieces.

In the embodiment of my invention shown by Way of examples in Figs. 1-4disks of circular shape, collectively designated 10 in Fig. 1, areprovided which are eccentrically mounted on the rotary shafts designated50-61, and are structurally aggregated into groups of 5, 4, and 3 disksrespectively. The material is fed through a hopper 40 and proceeds overthe bed of disks in the direction of the arrow 3:.

The aggregation of said disks into groups is conspicuous by the angulardisplacement of the latter relatively to each other: In Fig. do it isindicated how the groups of circular disks 10a, 1011 may be convenientlydisplaced relatively to each other by an angle of 180, while the groupsof disks 10a, 10a, 10a" and 10b, 10b, 10b" of adjacent shafts 59, 60, 61extend in the same direction in space i. e. the groups of disks ofadjacent shafts forming virtual angles of 0 relatively to each other.

Another important feature of my invention is the provision of auxiliarydisks 12 between the groups of disks of the individual shafts: As seenin Figv 4a between every 4 adjacent groups of disks low-10b and10a'-10b, there would be formed temporarily-twice during each rotationof the shafts-gaps having two pointed corners i, i, indicated in hatchedlines, through which correspondingly large pieces of the material wouldpass and drop down, thus unduly proceeding into a class of the materialthe diameter of the pieces of which should not exceed the normal widtha--b-c respectively between every two adjacent groups of disks, asindicated in Figs. 3 and 4. In order to overcome the said drawback saidauxiliary disks 12 of circular shape are inserted between every twoadjacent groups of disks 10a, 10b of each shaft and are concentricallyfixed on the latter; by this expedient the objectionable projectingcorners i, i are eliminated and a uniform width of the gaps is insured.

A subsidiary feature of my invention is the provision of stripping bars20 of improved design which are arranged between the disks and aredesigned to safeguard the apparatus against becoming choked, especiallyin cases when materials of a sticky nature and in moist condition suchas brown coal, lignite or the like are to be classified; said strippingbars fit around the rotary shafts and into the spaces between every twoadjacent disks and are secured tothe rotary shafts 5061 by resilienthooks 21 surrounding the shafts at an arc exceeding 180, so that theyare safe against becoming accidentally detached. In addition thereto thestripping bars 20 are fixed in their operative position by rods 22,extending across the classifying apparatus underneath the bed of disks,and are preferably provided with resilient arms 23 downwardly extendingfrom the hooks 22, so as yieldingly do their scraping sifying apparatussafer against becoming inadbars downwardly extending into the spacesbetween, the rotary disks at the feed end of the classifying apparatus,shown in Figs. 1 and 2. By said guide bars larger lumps of the materialdescending through the hopper are prevented from dropping over the rearend of the apparatus; the said guide bars will incidentally act asstripping blades for the disks of shaft 50, so that in this caseseparate stripping bars can be dispensed with. s

Various changes and modifications may be made in the structural detailsof classifying apparatus of improved design as described above and inthe shape and cooperation of their component parts, withoutsubstantially departing from the spirit and the leading ideas of myinvention and without sacrificing any advantages obtained thereby. I

Instead of bevel gears 70, shown in Figs. 2 and 3, gears of other typesmay be conveniently used for rotating the shafts 50-61 in the samedirection of rotation.

While circular disks 10 are a convenient shape,

easily and inexpensively to be manufactured,

disks of different design may be used instead andas seen in Figs. 5 and6with the same result viz, that the'gaps d and e between the cooperatinggroups of disks of two adjacent shafts will remain substantiallyconstant all through the rotary movements of the disks.

In Fig. 5 disks 15 of elliptical shape are shown, which will fulfill therequirements under consideration, if the cooperating groups of disks oftwo adjacent shafts 50', 51', 52', 53' are angularly displacedrelatively to each other by angles of 90; the angle of displacement'ofthe groups of disks 15 mounted on the individual shafts being also 90. 7

Another structural modification of the disks is seen in Fig. 6; saiddisks 16 are of the shape of equilateral triangles having outwardlybulging curved sides. The groups of said disks 16 of two adjacent shafts50", 51", 52", 53" are angularly displaced relatively to each other byangles of 0 while the angular displacement of the groups of disks 16 ofindividual shafts is equal to 60.

I am aware that classifying apparatus are known in the art in whichrotary cylinders of elliptical cross sectional form, extending acrossthe whole width of the bed of classifying apparatus are used, and inwhich the respective adjacent cylinders are angularly displaced to eachother for cooperation by an angle of 90, so that the gaps between thosecooperating cylinders will remain substantially uniform throughout theirrotating movements; and I make no claim to elliptically shaped cylindersper se except to their specific design in the form of disks ofrelatively short length and their specific step-forming arrangement ingroups set forth hereinbefore.

I am also aware that disks of the shape of equilateral triangles-buthaving straight sideshave become ,known in connection with classifyingapparatus of the type to which my invention relates; and I make no claimwhatever to such triangular disks.

What I claim is:

1. Classifying apparatus for the purpose set forth comprising incombination sets of spaced rotary shafts, the latter being arrangedsubstantialls parallel to each other, means for rotating said "shafts inthe same direction of rotation, spaced disks mounted on said shafts soas to form a bed of disks and to be revolved with the shafts, the disksof individual shafts being structurally aggregated into groups of whichalternate groups are angularly'displaced relatively to the intermediategroups of disks, so as to form steps, causing the material undertreatment to crosswisely roll over the bed of disks as the-disks rotate,the disks of adjacent shaftsof individual sets of shafts beingcooperatively arranged substantially in line with each other so as topresent gaps between their opposed circumferential edges, the form ofsaid disks and the angular position of the groups of disks of twoadjacent shafts relatively to each other being so chosen, that the gapsunder consideration will remain substantially uniform in widththroughout the rotary motion of the shafts.

2.. Classifying apparatus for the purpose set forth and having thefeatures outlined in claim 1, in which circular disks are provided,eccentrically arranged on the said rotary shafts, the stepsforminggroups of disks of the individual shafts being angularly displacedrelatively to each other by an angle of 180, while the cooperatinggroups of disks of adjacent shafts are angularly displaced relatively toeach other by an angle of 0.

3. Classifying apparatus having the features outlined in claim 1, inwhich elliptical disks are provided mounted on the rotary shafts in suchposition that the virtual centres of symmetry of the disks coincide withthe centres of the respective shafts, the steps-forming groups of disksof the individual shafts being angularly displaced relatively to eachother by an angle of 90, while the cooperating groups of disks ofadjacent shafts .are angularly displaced relatively to each other byangle of 90.

4. Classifying apparatus having the features outlined in claim 1, inwhich disks of the shape of equilateral triangles are provided, havingoutwardly projecting curved edges and being so mounted on the rotaryshafts that their virtual centres of symmetry coincide with the centresof the respective shafts, the groups of disks of the individual shaftsbeing angularly displaced relatively to each other by an angle of 60,while the cooperating groups of disks of adjacent shafts are displacedrelatively to each other by an angle of 0.

5. Classifying apparatus for the purpose set forth and having thefeatures outlined in claim 1, in which circular disks are provided,eccentrically arranged on the said rotary shafts, the groups of disks ofthe individual shafts being angularly displaced relatively to each otherby an angle of 180, while the cooperating groups of disks of adjacentshafts are angularly displaced relatively to each other by an angle of0, auxiliary circular disks being mounted between adjacent groups ofdisks of individual shafts concentrically to the latter.

forth and having the features outlined in claim 1, in which strippingbars are provided, downwardly extending into the spaces between thedisks of the extreme row of disks at the feed end of the apparatus andsnugly fitting over the respective rotary shaft.

HANS-JOACHIM JOHLIGE.

